110. More like thirty or forty, according to some--and I think there's some validity there.

(PhysOrg.com) -- New research from the UK shows the brain continues to develop after childhood and puberty, and is not fully developed until people are well into their 30s and 40s. The findings contradict current theories that the brain matures much earlier. Professor Sarah-Jayne Blakemore, a neuroscientist with the Institute of Cognitive Neuroscience at University College London, said until around a decade ago many scientists had "pretty much assumed that the human brain stopped developing in early childhood," but recent research has found that many regions of the brain continue to develop for a long time afterwards. The prefrontal cortex is the region at the front of the brain just behind the forehead, and is an area of the brain that undergoes the longest period of development. It is an important area of the brain for high cognitive functions such as planning and decision-making, and it is also a key area for social behavior, social awareness, for empathy and understanding and interacting with other people, and various personality traits. Prof. Blakemore said the prefrontal cortex “is the part of the brain that makes us human,” since there is such a strong link between this area of the brain and a person’s personality. Prof. Blakemore said brain scans show the prefrontal cortex continues to change shape as people reach their 30s and up to their late 40s. She said the region begins to change in early childhood and then is reorganized in late adolescence but continues to change after that.